Interlocking mechanism for elevator doors



Dec. 22, 1953 a. w. TUCKER, JR

INTERLOCKING MECHANISM FOR ELEVATOR DOORS Filed Feb. 29, 1952 2 Sheets-Sheet l Br f ATTORNEY Patented Dec. 22, 1953 INTER/LOCKING MECHANISM FOR ELEVATOR DOORS Benjamin Whitehead Tucker, Jr., South Orange, N. J., assignor to Otis Elevator Company, New York, N. Y., a corporation of New Jersey Application February 29, 1952, Serial No. 274,207

8 Claims.

The invention relates to an interlocking mechanism for elevator hoistway doors.

In elevator installations it is customary toprevent operation of the elevator car unless the hoistway doors at all landings are closed and locked. Thus movement of the elevator car away from a landing cannot take place until the hoistway door at that landing is closed and locked. This is accomplished by interlocking mechanism in which electrical contacts prevent the completion of operating circuits for the elevator car until the hoistway door is mechanically locked closed.

It is recognized that the zone in which the doors are locked may be diiferent when the elevator car is operated by an attendant than when the elevator car is operated without an attendant. If the elevator car is operated withoutan'attendant, safety precautions dictate that the elevator car beprevented from moving until the door is substantially in fullyclosed position and locked.

However, if the elevator car is attendant operated the safety afiorded the passengers is considered satisfactory if the door is locked and.

the car is permitted to operate upon the door reaching a point a short distance from closed position.

In certain types of elevator installations the elevator car is at times operated by an attendant while at other times the elevator car is operated without an attendant. Hence it is apparent that n a two zone hoistway door interlock will permit taking advantage of the difierent conditions set forth for attendant and non-attendant operated elevators. It is to this end that the present invention is directed.

The object of the inventionis to provide a simple, compact, reliable two zone interlocking mechanism.

In carrying out the invention according to the arrangement which will be described, a catch is mounted for rotative movement in accordance with movement of the hoistway door. A pair of pivotally mounted latch members are biased to engage a locking surface formed on the catch to lock thedoor. One of these members engages the locking surface to lock the door as. it reaches a position considered'sufficiently closed'for attendant operation, while the other engages the r locking surface to lock the" door when the door reaches substantially fully closed position for without attendant operation. Each of these latch members is arranged to operate interlock con-' tacts toenable the car to be operated when the door is closed and locked. The selection of thecontacts which are effective-is acoomplished'preierably through the use of a throw-over switch. The latch members may be released to unlock the I door when a stop is made at a floor as by a retiring cam carried by the car. The retiring cam acts directly to release the first latch member which in turn releases the second latch member from locking engagement with the catch. Prior to the door being closed, the retiringcarn is withdrawn and the latch members rest on a raised arcuate surface of the catch. In this manner the interlock contacts are held in an open circuit condition until the latch members engage the locking surface of the catch. In the arrangement illustrated in the drawings, catch and latch members are arranged in a housing secured to the header of the hoistway door framework. Rotative movement of the catch in accordance with door movement is effected by a door arm pivotally connected at one end to the door and pivotally mounted at its other end on the door header. The catch is secured to the other end of the door arm for rotative movement thereby as movement of the door takesplace. The closing of the door may be effected by a spring secured to the catch which is placed in tension when the door is in open position to enable it toact through the catch and door arm to efiect the doorclosing operation.

A'general idea of the invention and various features and advantages thereof will be gained from the above statements. Other features and advantages will be apparent from thefollowing Figure 5'is a view taken along line 5-5 of Fig-r Figure 6 is a view taken along line t-tof 1 Figure 4;

Figure 7'. is a schematic View of the locking mechanism when the doors are open;

Figure 8 is a schematic view of the locking mechanism when the'doors have just been locked in the first interlock zone; and 1 v Figure 9 is a schematic view of the locking mechanism when the doors have just been locked in the second interlock-zone. a

Referring first to Figures 1, 2 and 3, the interlock mechanism is shown in its relationship to the elevator car and the hoistway door. The hoistway door it at the landing for which interlock mechanism 5 l is shown is a single speed side opening slide type door supported on track i2 through the intermediary of hangers I3. The door may be operated either manually or by means of a door operator. For purposes of illustration, the door will be described as power operated. The door operator i i shown schematically on the elevator car l5 acts through an arm I6 and link I? to operate the elevator car door It, the hoistway door being connected by clutch mechanism to the car door for operation by the door operator.

The interlock mechanismis mounted on the hoistway door header 2|. In this position the interlock requires no space in back of the door or on the side of the car. A housing 22 for the mechanism is secured to the header as by screws 23. A catch 2-! is rotatably mounted on a pin 25 secured to the back plate 26 of the housing (see Figure 6). The catch is rotated through a door arm 21, one end of which is rigidly fastened to the catch and the other end of which is pivotally connected to the hoistway door It at 38 through a link 3i. As the door is opened or closed, the catch is rotated. The catch, and consequently the door itself, is biased to a door closed position by door spring 32. The door spring is anchored to the hoistway door header by angle bracket 33, nuts 34 and bolt 35 and is secured to the catch through chain 36.

Referring also to Figures 4, 5 and 6, a preferred arrangement of the catch 24 is shown in the form of a disc having recess 3! formed in the upper portion thereof. A pair of latch members and Al in the form of levers of laminated construction are pivotally mounted on pins 42 and 43 secured to the back plate 26 of the housing and held in place by clips 44. Latch member 40 is formed with a latch arm having a hook 45 and latch member 4! is formed with a latch arm having an abutment 46 for engaging the locking surface 41 of recess 3'! to lock the door. Each of the latch members locks the door at a different point of door travel, the zones in which the door is locked by the different latches being termed interlock zones. Indicative that the door is closed and locked in the interlock zone, interlock contacts for that zone are closed and elevator operating circuits may be energized therethrough. These interlock contacts are part of interlock switch assemblies 55 and 5| operated by the latch members 40 and M respectively.

As may be seen from Figure 4 these switch as semblies are similarly constructed, hence only asthe bridge and a cup washer 62 also slidable on the member. An arm 63 formed on the latch member #30 is pivotally secured to member 51 by a pin 65. Spring 65 is arranged in a compressed state on the shank of member 51 between an abutment 66 secured to back plate 26 and a washer 61 beneath arm 63. With this a1'range-.

ment, spring 65 biases the latch member to looking position and the contact bridge to a position to bridge the stationary contacts 52. A bumper (58 secured to base 53 limits movement of latch member 40 into recess 31 and also limits the compression of contact bridge 55.

The unlocking of the latch member 4i! and the opening of the interlock contacts of assembly 53 is efiected by a push rod it which connects latch member 40 to a lever H. This lever is provided with an'operating roller 72 to be engaged by the retiring cam 13 carried by the elevator car. The retiring cam is connected by a chain it to an operating device '25, also carried by the car. The cam is in the form of a flat plate having a pair of angularly disposed parallel slots it. Arranged in each slot is a ball bearing roller Ti, these rollers being secured to a bracket mounted onthe car. The cam slides on these rollers as it is retracted and released by the operating device. As somewhat schematically illustrated in Figure 3, a switch is arranged to be operated by the retiring cam as it reaches its extended position. As the retiring cam is released, it acts through roller '52, lever H and push rod it, to rotate latch member 40 clockwise against the force of spring 85. This unlocks latch member as from the catch and opens the interlock contacts 52 of switch assembly 5i Latch member M is provided with a pin 82 in position to be engaged by latch memher so. The unlocking of latch member 45 and the opening of the interlock contacts 85 of assembly 5i against the force of spring 33 is efiected by engagement of latch member 45 with pin 82 as the unlocking of latch member it takes place. With the latch members withdrawn from the recess, the catch is free to rotate and the doors may be opened.

With the doors in open position, catch 24 is in a position such that latch members 40 and ii are held above the cylindrical surface 84 of the catch as shown in Figure '7. Preparatory to a door closing operation, the retiring cam operating device is energized to withdraw the cam. As the cam moves away from the roller, lever H rotated clockwise by springs 65 and 83 until the latch members engage the cylindrical surface of the catch. As the doors are closed, door arm 21 is moved clockwise to rotate the catch. The latch members ride on cylindrical surface 84 of the catch until the hoistway door reaches a position such that the leading door edge is at the predetermined position defining the first interlock zone. As this point is reached latch member it drops into the recess in the catch and engages locking surface 47, thus'preventing the door from being reopened beyond this interlock zone as shown inFigure 8. Immediately after the hoistway door is locked in the first interlock zone, interlock contacts 52 are closed. Complete closing of the hoistway door is insured by door spring 32 which acts on catch 24 through chain 35, or by the door operator.

catch to engage latching surface il when the door reaches full closed position as shown in Figcatch formed by the cylindrical'suriace 36 may be only long enough to support the latch members when the retiring cam is retracted and the door is out of closed position. 1

Further movement of the door toward full door closed position resultsin latch member at dropping into the recess in the In operation, assume that the elevator car is stopped at a landing and that the car and the hoistway doors have just closed. Under such conditions, the retiring cam operating device is energized and the retiring cam is in its retracted position out of engagement with roller 72 thus allowing the latches to move into recess 31 in catch 24 to lock the hoistway door and close the interlock contacts enabling the car to start. As the elevator car arrives at the landing at which a stop is being made, the retiring cam. operating device i5 is deenergized, thus releasing the retiring cam. As the retiring cam is extended, it engages the roller 72 and causes movement of the push rod 70 to move thejlatch members out of the recess 3? of the catch. The hoistway door is now closed but unlocked. The retiring cam switch is utilized to cause the energization of the door operator motor to open the doors. With the doors open, the latch members 66 and 4! are re: tained in position above the cylindrical surface 84 of the catch by the retiring cam. When the doors start to close, operating device 15 is energized withdrawing the retiring cam 73 from engagement with the roller 52. This releases the latch members which come to rest on the cylindrical surface of the catch. When the door reaches the first interlock zone, the first latch member is moved into recess 3'! to engage the locking surface 47 of the catch. Immediately after the door is looked in the first interlock zone,

the interlock contacts 52 for this zone are closed. If the elevator car is under the control of an attendant, closing of these contacts permits energization of the elevator car operating circuits and consequent movement of the car away from the landing in response to a call. Under such circumstances, complete closing and locking of the door in its full closed position would be assured by the door spring. Movement of the door toward full closed position results in the second latch member engaging the locking surface of the catch when the door enters the second interlock zone. Immediately after the door is locked in this zone, the interlock contacts 85 for this zone are closed. For elevator cars which are operated without an attendant, closing of the second interlock zone contacts must be complete before the elevator car can move away from a landing.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Locking mechanism for closure means controlling access to an elevator car comprising: a catch member rotatable in accordance with movement of said closure means, said member having a raised arcuate portion to provide a shoulder; and a plurality of latch members to cooperate with said shoulder to successively lock said closure means at different positions.

2. Interlocking mechanism for closure means controlling access to an elevator car comprising: a member rotatable in accordance with movement of said closure means having a catch and a raised arcuate portion; a plurality of latch members for successively engaging said catch to lock said closure means at different positions; a retiring cam; means actuated by said cam when extended to release said latch members from said catch to unlock said closure means, said latch members being supported on said raised arcuate portion when said closure means is out of closed position and the retiring cam is retracted; and a plu-.

rality of switching mechanisms individually actuated by said latch members upon extension of said cam and maintained in such actuated condition when their respective latch members are supported by said raised arcuate portion.

'3. Interlocking mechanism for an elevator hoistway'door comprising: a catch memberxrotatable in accordance with hoistway door movement and having a raised arcuate portion which forms a shoulder; a pivotally supported first latch member biased to lock said hoistway door in a first interlock zone by engaging said shoulder; an interlock switch operated by said first latch member, said interlock switch being in open condition when said first latch member is out of engagement with said shoulder; a pivotally supported second latch member biased to lock said hoistway door in a second interlock zone by engaging said shoulder; an interlock switch operated by said second latch member, said interlock switch being in open condition when said second latch member is out of engagement with said shoulder; retiring cam means for moving said first latch member out of engagement with said shoulder; and means operated by movement of said first latch member out of engagement with said shoulder for moving said second member from engagement with said shoulder.

a. Interlocking mechanism for closure means controlling access to an elevator car operating in a hoistway comprising; :a catch member supported by the hoistway wall at said closure means and having a recess therein; a first latch member pivotally supported by the hoistway wall and having an arm for entering said recess when said closure means reaches a point a predetermined distance from full closed position; a first interlock switch actuated by said first latch member; a second latch member pivotally supported by the hoistway wall and having an arm for entering said recess when said closure means reaches a second point closer to full closed position; and a second interlock switch actuated by said second latch member.

5. Interlocking mechanism for an elevator hoistway door having a door framework secured in the hoistway wall, said mechanism comprising; a housing mounted on said framework within the hoistway; a catch member having a recess therein to form a locking surface, said catch member being rotatably supported in said housing for movement in accordance with hoistway door movement; a first latch member pivotally supported in said housing and having a latch arm biased to move into the recess to lock the hoistway door at a predetermined point during door closing travel; a first interlock switch mounted in the housing, the contacts of which are closed by movement of the latch arm of said first latch member into said recess; a second latch member pivotally supported in said housing and having a latch arm biased to move into said recess to lock the hoistway door at a second predetermined point during door closing travel; and a second interlock switch mounted in the housing, the contacts of which are closed by movement of the latch arm of said second latch member into said recess.

6. Interlocking mechanism for an elevator hoistway door having a door framework secured framework; a circular catch member rotatably supported within said housing for rotative movement in accordance with movement of said hoistway door, said catch member having a recess therein to form a locking surface; a first latch member formed with an arm having a hooked end, said latch member being biased so that said hooked end engages said locking surface to lock the hoistway door when the door reaches a first interlock zone during door closing travel; a first interlock switch connected to said first latch member and operated thereby so that contacts of said switch are closed when said hooked end engages the locking surface; a second latch member formed with an arm having an abutment and biased so that said abutment engages said looking surface to lock the hoistway door when the door reaches a second interlock zone during door closing travel; and a second interlock switch connected to said second latch member and operated thereby so that the contacts of said switch are closed when said abutment engages said looking surface.

7. Interlocking mechanism for an elevator hoistway door mounted at said hoistway door, said mechanism comprising; a catch member having a recess therein; a pivotally supported first latch member biased to move into said recess when said hoistway door is in a first interlock zone; an interlock switch operated by said first latch member; means carried by the elevator car for moving said first latch member out of said recess; a pivotally supported second latch member biased to move into said recess when said hoistway door is in a second interlock zone; a second interlock switch operated by said second latch member; and means operated by movement oi said first latch member out of said recess for moving said second latch member out of said recess.

8. Interlocking mechanism for an elevator hoistway door having a door framework secured in the hoistway wall, said mechanism comprising; a door arm, one end of which is connected to said hoistway door and the other end of which is rotatably mounted on the hoistway door framework; a catch member secured to said other end of the door arm to be rotated thereby in accordance with hoistway door movement, said catch member being formed with a recessed locking surface; a door spring acting through said catch member and said door arm to bias said hoistway door to door closed position; a pivotally mounted first latch member biased for engagement with said recessed locking surface to lock said door in a first interlock zone; an interlock switch directly operated by said first latch member; a pivotally mounted second latch member biased for engagement with said recessed locking surface to lock said door in a second interlock zone; a second interlock switch directly operated by said second latch member; and means for moving said latches out of engagement with said locking surface to unlock said door.

BENJAMIN NmEHEAD TUCKER, JR.

0 reference cited. 

